The invention relates to circuit breakers, and more particularly to high-speed circuit breakers.
In testing power GaAs MESFETs, it is necessary to identify the location of a failure to discover the causes of the failure. However, these devices fail catastrophically in an extremely short time. For example, after a GaAs MESFET begins to short, the damage will be so extensive after a few tens of nanoseconds or less that no information can be obtained on the location of or reason for the failure. To analyze the failed device, it is necessary that power be turned off as fast as possible after the failure begins.
It is known to protect a device using a crowbar circuit which essentially shorts across the device under overload conditions, thereby shunting power away from the device. This has been accomplished by using, e.g., SCR's. However, a crowbar circuit using an SCR as the shorting device is not fast enough to protect a GaAs MESFET because an SCR has a response time measured in microseconds, rather than in nanoseconds.
An object of the present invention is to provide a circuit breaker which can trip within tens of nanoseconds or less after an overload condition has been detected.
Another object is to provide such a circuit breaker which can momentarily absorb high currents.
Yet another object is to provide a cost-effective, high-speed circuit breaker.
Yet still another object is to generally improve on known devices.